Advertisement
Social Justice

Do the TikTok plant pot candle heaters work? We asked a thermodynamics expert

With energy bills soaring, candle heaters are sweeping TikTok as a cheap way to heat your home. We found out if they work – and if they’re safe

Energy bills are soaring so it’s only natural that heating your home on the cheap is tempting. It’s no surprise, then, that a new life hack has taken TikTok by storm: the terracotta candle heater.

It involves putting a tea light underneath an upturned terracotta pot (so the smallest bit of the pot is at the top) with the result supposedly warming your room.

The basic theory goes that it’s some kind of super-heater and will heat your room up. Ingenious, right?

Here’s the science behind whether it works, and if it’s safe.

Subscribe to The Big Issue

Support us

Take a print or digital subscription to The Big Issue and provide a critical lifeline to our work.

Do terracotta candle heaters work?

If you’re wondering whether it’ll heat your room, the answer is: not any more than a candle would.

Let me introduce you to the laws of thermodynamics.

Advertisement
Advertisement

The first law says that energy cannot be created or destroyed within a system. Heat is a form of energy.

So if you’re putting a candle in a terracotta pot, lighting it and not doing anything else, you can’t generate more energy than was originally there. On a very basic level, the terracotta candle heater can’t “amplify the heat” because you’re not adding any energy.

“In layman’s terms, you cannot create energy. So, a ‘free lunch’ is not possible,” Erich A Muller, professor of thermodynamics at Imperial College London, told the Big Issue.

It’s only natural the “heater” will make the room hotter – but it’s insulation that will keep it warm, Muller added. “This combustion generates heat and will raise the temperature of the space,” he said.

“The terracotta is just forcing some of the warm air from the candles to stay in place and not dissipate so rapidly, but it is doing nothing additional other than the illusion of a little heater,” Muller added.

“If you really want to save energy, there are no silver bullets: double glaze the windows, draft-proof the doors, insulate the walls cavities and ceiling, and use efficient heaters – for example, ditching the electric heater for gas or, better yet, for heat pumps.”

You might also think that by heating up the terracotta pot, you’re allowing the heat to be released over a longer period of time than you would with the candle, and allowing the room to heat up properly.

Your support changes lives. Find out how you can help us help more people by signing up for a subscription

Not so, Muller said: “There is no difference in the final result if you heat the space slowly or rapidly.”

So, pretty comprehensively, the terracotta heater method isn’t actually very effective as a heater.

And here’s what literal firefighters say about doing that…

Are plant pot candle heaters safe?

No – fire services have strongly warned against using them.

Charlie Pugsley, the London Fire Brigade’s Assistant Commissioner, said his service sees devastating results when things go wrong for people trying to heat their homes on the cheap.

“Candles are one of the most common causes of fires in the home and they shouldn’t be used for anything other than their intended purpose. Although life hacks can be handy, so many of them have the potential to be dangerous and we would urge people not to follow videos online if they could put you or others in danger,” Pugsley said.

“We would always recommend people swap to using safer LED candles rather than flame ones, but if you are using them they should never be left unattended.”

Get the latest news and insight into how the Big Issue magazine is made by signing up for the Inside Big Issue newsletter

Pugsley also recommended making sure you have working smoke alarms and getting clued up on what to do if there is a fire

He added: “If you’re struggling to pay your energy bills, Citizens Advice can give you information on grants and benefits that can help you.”

Break the cycle of poverty for good
Big Futures is calling on the Government to put in place a plan and policies to break this cycle of poverty for good. We are calling for long-term solutions to meet the biggest issues faced in the UK today – the housing crisis, low wages and the climate crisis. Dealing with these issues will help the UK to protect the environmental, social, economic and cultural wellbeing of future generations. So that young people and future generations have a fair shot at life. Join us and demand a better future.

It’s not just the risk of fire with plant pot candle heaters. A Scottish Fire and Rescue Service spokesperson warned that: “We would always strongly discourage the use of any homemade heating device. This could present the risk of accidental fire within the home and the potential of Carbon Monoxide poisoning.”

So all the evidence and expert advice points to quite a simple conclusion. Don’t do it.

Advertisement

Every copy counts this Christmas

Your local vendor is at the sharp end of the cost-of-living crisis this Christmas. Prices of energy and food are rising rapidly. As is the cost of rent. All at their highest rate in 40 years. Vendors are amongst the most vulnerable people affected. Support our vendors to earn as much as they can and give them a fighting chance this Christmas.

Recommended for you

Read All
Four in five of the children’s homes in England are run for profit – here’s why that is a problem
Child poverty

Four in five of the children’s homes in England are run for profit – here’s why that is a problem

The cost of living crisis is making it harder for domestic violence victims to leave their abusers
Domestic violence

The cost of living crisis is making it harder for domestic violence victims to leave their abusers

The domestic violence charities supporting survivors in the UK
Domestic violence

The domestic violence charities supporting survivors in the UK

Social mobility Tsar Katharine Birbalsingh blames lack of progress on government chaos
Social mobility

Social mobility Tsar Katharine Birbalsingh blames lack of progress on government chaos

Most Popular

Read All
Here's when and where nurses are going on strike
1.

Here's when and where nurses are going on strike

Pattie Boyd: 'I was with The Beatles and everything was fabulous'
2.

Pattie Boyd: 'I was with The Beatles and everything was fabulous'

Here's when people will get the additional cost of living payment
3.

Here's when people will get the additional cost of living payment

Why do people hate Matt Hancock? Oh, let us count the ways
4.

Why do people hate Matt Hancock? Oh, let us count the ways